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WineEast 80 60 40 20 Disease Severity and Sunlight Chardonnay Chancellor Exposed UV Filter Shade Cloth but also from the heating effect of direct sunlight. Clusters were in- oculated with PM spores at 75% capfall. As shown in Figure 2 (this page), we found that removing UV radiation with the Plexiglas filter increased disease severity on fruit by 50%-500% for both varieties and locations. The Chancellor shade cloth treatment, which elimi- nated both the increase in surface temperature and UV radiation, further increased disease severity in one of the two experiments. Sunlight manipulation in the vineyard Year 1 Finger Lakes Year 2 Year 1 Year 2 Finger Lakes Year 1 Yakima Figure 2: Percentage of disease severity on Chancellor and Chardon- nay vines receiving full solar radiation (exposed), sunlight from which 95% of the UV radiation had been filtered (UV filter) or sunlight reduced to 20% of ambient via neutral density (shade cloth). Center in Prosser, Wash., with the assistance of Dr. Gary Grove and his staff. Plexiglas blocks UV radiation but permits passage of the sunlight wavelengths that elevate surface temperature. At the Chancellor vineyard in Geneva we also suspended shade cloths over other vines to shield them not only from UV radiation SpiritedShipper_Dir11.qxp 10/6/10 10:52 BDI_Nov10.qxp 9/29/10 11:50 AM Page 1 Given that UV radiation and sun exposure reduce PM, how can we use this information to better manage the disease? We examined this question in a young Chardonnay vineyard in New York by com- paring two training systems—Vertical Shoot Positioning (VSP) and Umbrella-Kniffen (UK)—and removing basal leaves around clusters to provide different levels of light exposure in the fruiting zone. UK provided more shoots per linear foot of row than VSP, hence more potential for canopy shading in the fruit zone. Within each training system, we removed basal leaves at two dates: Two weeks post-bloom (fruit set) and five weeks post-bloom. We inoculated clusters with powdery mildew spores at bloom and rated PM severity in each treatment. We found that both factors affected PM severity. (See Figure 3, page 54.) First, powdery mil- dew severity was lower in the VSP than in the UK training system, regardless of leaf-pulling treatment. Second, leaf removal at fruit set significantly reduced the amount of disease in both training systems, but leaf removal five weeks after bloom had no effect. U.S. Patent Numbers 5,730,289 & 5,967,294 • All our shippers are made with extra cushioning to prevent breakage THE ORIGINAL SHIPPER • UPS & FEDEX approved • For spirited shipments up to 12 bottles • Magnum size shippers up to 6 bottles • Fits bottles up to 5"diameter to 16"tall • Costs less, more durable than styrofoam • Gift Boxes •Gift Bags •Wooden Gift Boxes 100% ENVIRONMENTALLY FRIENDLY – GO GREEN! spiritedshipper.com 800-730-SHIP (7447) Wines & Vines MARCH 2011 53 Fruit Disease Severity %